/*
 * Copyright (c) 2014, Petr Panteleyev <petr@panteleyev.org>
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 *    1. Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *    2. Redistributions in binary form must reproduce the above copyright notice,
 *       this list of conditions and the following disclaimer in the documentation
 *       and/or other materials provided with the distribution.
 *    3. The name of the author may not be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.panteleyev.gpg;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 *
 * @author Petr Panteleyev <petr@panteleyev.org>
 */
public class GPG {
    private final String binary;
    
    private GPG(String binary) {
        this.binary = binary;
    }
    
    public static GPG newGPGService(String binary) {
        return new GPG(binary);
    }
    
    public String encrypt(String text, String key) throws IOException {
        final String cmd = binary + " -e -a -r " + key;
        final StringBuilder b = new StringBuilder();

        final Process p = Runtime.getRuntime().exec(cmd);
        
        try (final OutputStream out = p.getOutputStream()) {
            out.write(text.getBytes());
            out.flush();
        }

        try (final InputStream in = p.getInputStream()) {
            while (true) {
                final int i = in.read();
                if (i == -1) {
                    break;
                }
                b.append((char)i);
            }
        }
        return b.toString();
    }
    
    public String decrypt(String text, String passphrase) throws IOException {
        final String cmd = binary + " -d --batch --passphrase " + passphrase;
        final StringBuilder b = new StringBuilder();
        
        final Process p = Runtime.getRuntime().exec(cmd);
        
        try (final OutputStream out = p.getOutputStream()) {
            out.write(text.getBytes());
            out.flush();
        }

        try (final InputStream in = p.getInputStream()) {
            while (true) {
                final int i = in.read();
                if (i == -1) {
                    break;
                }
                b.append((char)i);
            }
        }
        
        return b.toString();
    }
}
